yes it is a keyboard....but it is not a synth bass sound. It is actually vocal samples pitched down and filtered. Back when Seinfeld was in production I remember seeing an interview piece with whoever the guy was (don't remember his name, but it was not Jonathan Wolfe...) Yep Vocal samples mangled and spewed back out (some even backwards!)
Max

Composer/conductor/arranger Henry
Mancini was one of the most versatile
talents in music. The Mancini name,
synonymous not only with great
motion picture and television music,
but with fine recordings and

Whether it be a complete score or a featured song, Mancini lent his talents to
many memorable films including Victor/Victoria, The Glass Menagerie, The Pink
Panther, 10 Darling Lilli, Arabesque, Charade, Days of Wine and Roses, Hatari
and Breakfast at Tiffany's.

He also wrote for a number of television films including "The Thorn Birds," and
"The Shadow Box," as well as television themes including "Peter Gunn," "Mr.
Lucky," "NBC News Election Night Coverage," "Newhart," "Remington Steele,"
and "Hotel."

Not familiar with any of those shows/themes apart from Seinfeld and Northern Exposure, which is still one of my favourite TV shows of all time. If I ever get me a fretless, that's what I'll be playing on it.